Eight former police officers involved in the Cardiff Three miscarriage of justice murder case have cast doubt on the freed men’s innocence as they sue their own force over the saga.

The ex-officers are taking legal action against South Wales police after they were prosecuted over the way they investigated the 1988 murder of the Cardiff sex worker Lynette White, which led to the wrongful conviction of three men.

On the first day of the officers’ civil case, their lawyer argued that the man now serving life for the murder, Jeffrey Gafoor – a client of White’s – may have had at least one accomplice.

Anthony Metzer QC said: “The question of whether [Gafoor] was acting alone is very much alive. Yes, the three original defendants were acquitted, but there’s a world of difference between a charge being quashed and actual proof of not being guilty.”

Metzer also said that the eight officers who were prosecuted were “scapegoats” and alleged there was a “crusade” against them from their own force following media pressure over the case.

White, 20, was stabbed more than 50 times at the flat where she worked in 1988. Stephen Miller, Yusef Abdullahi and Tony Paris were convicted of her murder in 1990 and jailed. Their convictions were quashed two years later and the men, nicknamed the Cardiff Three, were released. In 2003, Gafoor admitted murdering White and is now serving a life sentence.

In 2011, the eight former officers were tried for “acting corruptly together” to make a case against the Cardiff Three. Prosecutors claimed their case was “largely the product of the imagination” and Gafoor was brought from prison to confirm that he acted alone when he killed White.

The former police officers – Graham Mouncher, Richard Powell, Thomas Page, Michael Daniels, Paul Jennings, Paul Stephen, Peter Greenwood and John Seaford – all denied conspiring to pervert the course of justice and the trial, the biggest of its kind against British police officers, collapsed.